Each year 1.1 million new cases of breast cancer occur among women worldwide and 400,000 women will die from this disease (www.uicc.org, www.who.int). Although progress has been made in preventing deaths by breast cancer in women, we still do not understand the biology of breast cancer at a level that would explain why certain patients respond well to therapy, whereas others develop recurrent disease with an inexorable downhill course. Improved treatment options are urgently needed to end this stalemate. Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer that lacks therapeutic options. TNBCs are defined by low expression of the estrogen, progesterone and HER2 receptors. Clearly, prognosis and predictive markers as well as novel treatment options are needed.